Soundings: Green bile: Should you worry?

Spring is in the air and the kids are arriving so fast you’re bouncing from room to room quicker than an Easter Bunny with a chocolate high. Towards the middle of your shift, as you grow weary of giving your “It’s a virus and it will get better on it’s own without the antibiotics your pediatrician prescribed” speech, you pick up the chart for a 5 month old with a triage complaint of “Green vomit”.

Your patient’s mother states that her son was well until this morning. He has vomited green emesis nine times and has had intermittent pain. There has been no fever, trauma or recent URI and the last BM was yesterday and appeared normal. The child is otherwise healthy and fully vaccinated. Mom shows you a bright green vomit stain of her son’s bib (Image 1). On exam he appears happy, comfortable and has a benign abdomen. Vital signs are fine and he appears well hydrated. On your way out to order a UA and a KUB you tell the mom to get you or a nurse if the baby vomits again or starts crying.

The KUB is read by the radiologist as negative (Image 2). You tell him you are worried about intussusception and request an air or contrast enema, to which he responds “You don’t need it. There is no way this kid has an intussusception (See Pearl #5 on next page).” Back at the bedside the kid looks great and the abdomen is benign, but you remember what Whittier Bill said, “If you are worried about intussusception, do the rectal exam early. There may be no history of currant jelly stool, but in every case of intussusception I have taken care of there has been either occult or gross blood on rectal exam.” You do the rectal exam and there is gross blood. You call back the radiologist and let him know to warm up his enemator.

Since you are always trying to improve your ultrasound skills, and you heard that ultrasound can be used to diagnose intussusception, you decide to take a look with the ED ultrasound machine. Here is an image of the RUQ (Image 3).

What do you see?

What next? See next page for conclusion.

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The KUB shows a non-obstructive gas patterns, but there is a paucity of air, which is consistent with intussusception. Your ultrasound image shows the classic “Target” or “Donut” sign of intussusception formed by the concentric loops of bowel (Image 4). The Gastrografin enema is diagnostic (Image 5), and, after three attempts, therapeutic. The rectal bleeding finally gives way to a rush of bile. Your radiologist eventually calls back and concedes that you made a good call.

I hope none of you will ever be in a situation where you would need to rely on your own skills to diagnose intussusception with ED ultrasound. This is not really part of the skill set anyone is recommending for the EP. However, if you think you feel a sausage in the right upper quadrant and you want to “take a look” to improve your skills and augment your physical exam, I see no harm. Moreover, it is nice to know that if you have a good ultrasound tech, this imaging modality is a great way to confirm the diagnosis without exposing the patient to additional radiation. You might even convince your radiologist to reduce the intussusception using an ultrasound-guided enema rather than the standard technique with air or contrast.

Continue Next for Pearls and Pitfalls

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ULTRASOUND PEARLS & PITFALLS FOR INTUSSUSCEPTION:

Know your limitations: Ultrasound may help clarify findings elicited by a thorough history and physical exam. When used correctly, it can greatly improve diagnostic accuracy, and help guide patient management, especially for time-critical diagnosis and treatment of unstable patients. If you use ultrasound in your ED, your department should have a quality improvement program set up that is approved by both ED administration and radiology.

Scan the sausage: The intussusception usually sits in the right upper quadrant. If you feel something that is shaped like a sausage, that’s the best place to start your scan. You are looking for a “target sign” or “donut sign” of one concentric cross section of bowel within another.

Know the pros and cons: Ultrasound has a reported sensitivity of 85% and specificity of 98% for intussusception and is radiation-free. However, it is not therapeutic. Consider it’s use when you are not worried that it will cause a significant delay or when attempts at radiographic reduction are contraindicated. Since it is a rare condition, the skill level and experience of the sonographer may play a large role.

Know your other studies: X-ray is not sensitive, but may show obstruction or decreased stool or air in the right lower quadrant. A CT scan can diagnose intussusception, but is not a first line study; consider its use when other conditions, such as appendicitis, are also high on your list of differential diagnoses. The study of choice is an air or gastrografin enema, which is diagnostic as well as therapeutic in most cases.

Heed Pregerson’s Rule: This rule boils down to not trusting the consultant when your gut tells you they are wrong. It states “When the consultants says there is no way that a patient has disease-X the risk for disease-X doubles.” Corollary: “If the consultant is an orthopedist or a radiologist the risk quadruples.”

Practice Makes Perfect: With bedside ultrasound there is no substitute for experience. The more ultrasounds you do, the better you will be able to differentiate abnormal from normal, even when you may not be sure exactly what the abnormality is. Take a look at the abdomen of the next pediatric patient you see with abdominal pain. Most of us probably wouldn’t recognize an inflamed appendix, intussusceptum or hypertrophied pylorus if it was staring us in the face in the middle of our screen, but you might! Either way, it’s a good idea to practice on kids just like adults. You don’t want a sick trauma case to be your first time sounding your way through the pediatric abdomen. An image library of normal and abnormal ultrasounds helps immensely and EPMonthly.com can take you there. Just go to www.epmonthly.com, select “Departments”, chose “Real-Time-Readings” and click on the “Ultrasound Library” link.